High-temperature-resistant polyurethane pouring sealant for fuel cell humidifier and preparation method of high-temperature-resistant polyurethane pouring sealant

Abstract

The invention discloses a high-temperature-resistant polyurethane pouring sealant for a fuel cell humidifier and a preparation method of the high-temperature-resistant polyurethane pouring sealant, and belongs to the technical field of high polymer materials. Raw materials of the high-temperature-resistant polyurethane pouring sealant for the fuel cell humidifier comprise a component A and a component B. The component A comprises low-unsaturation-degree medium-high molecular weight polyether, polytetramethylene ether glycol, polyoxypropylene glycol and the like, and the component B comprises hexamethylene diisocyanate, aromatic blocked polyisocyanate and the like. The preparation method comprises the following steps: mixing low-unsaturation medium-high molecular weight polyether, polytetramethylene ether glycol, polyoxypropylene glycol and the like to obtain a component A; mixing hexamethylene diisocyanate, aromatic blocked polyisocyanate and the like for reaction to obtain a component B; and mixing the component A and the component B, pouring the mixture into a mold, and curing to obtain the high-temperature-resistant polyurethane pouring sealant. The pouring sealant provided by the invention has good high temperature resistance and moisture resistance, and does not deform or crack when working at a high temperature for a long time.

Description

Technical Field

[0001] The invention relates to the technical field of polymer materials, and in particular to a high-temperature resistant polyurethane potting adhesive for a fuel cell humidifier and a preparation method thereof. Background Art

[0002] As an innovative power generation technology, hydrogen fuel cells have shown great potential and application prospects. Compared with traditional power generation methods that rely on fossil fuels, hydrogen energy not only provides higher energy conversion efficiency, but also has won wide attention for its clean characteristics. Its working process produces almost no harmful pollutants, and the only byproduct is water, which makes hydrogen fuel cells an important force in promoting global sustainable development goals.

[0003] The basic operating principle of fuel cells is extremely efficient. When hydrogen flows into the anode, the catalyst causes it to split, generating hydrogen protons (H+) and free electrons (e-). The free electrons flow through an external circuit to provide electrical energy to the load, while the hydrogen protons migrate through the proton exchange membrane (PEM) to the cathode. At the cathode, the hydrogen protons combine with oxygen ions entering through the electrolyte membrane to form water and release electrical energy. This simple and effective reaction process demonstrates the huge potential of hydrogen fuel cells.

[0004] However, the performance of the proton exchange membrane directly affects the overall efficiency and durability of the fuel cell. In the operation of the battery, it becomes particularly important to maintain the proper degree of humidification of the proton exchange membrane. This is not only because the conductivity of the membrane will be better in a wet state, but also because an overly dry membrane is prone to aging and failure. Therefore, the introduction of the humidifier becomes a key component to ensure the stability of membrane operation. The humidifier must not only be able to work effectively in a high temperature and high humidity environment, but also have excellent material properties to achieve long-lasting stability.

[0005] In the design of humidifiers, the selection and application of potting compounds are crucial. Humidifiers need to withstand long-term high temperature and high humidity environments, so potting compounds must have high-strength high temperature and high humidity resistance. In addition, it must have good adhesion to the polymer shell. If the adhesion is insufficient, it may cause separation and cracking between the humidifier and the shell, which in turn affects the operating efficiency and service life of the hydrogen fuel cell. Therefore, ongoing research emphasizes the selection of high-performance materials and their scientific application to ensure the stability of the humidifier in long-term use.

[0006] The technical development of hydrogen fuel cells not only relies on the coordinated optimization of various components, but also the performance improvement of humidifiers and their potting glue is the key. The potting glue in the existing technology often has poor high temperature resistance and poor mechanical properties. When the hydrogen fuel cell generates heat, the potting glue is prone to deformation or cracking. Summary of the invention

[0007] The purpose of the present invention is to overcome the above technical deficiencies, provide a high temperature resistant polyurethane potting glue for fuel cell humidifier and a preparation method thereof, and solve the technical problems of poor high temperature resistance and mechanical properties of the potting glue in the prior art.

[0008] In order to achieve the above technical objectives, the technical solution of the present invention provides a high-temperature resistant polyurethane potting glue for a fuel cell humidifier, wherein the raw materials include component A and component B, wherein the component A includes low-unsaturation medium-high molecular weight polyether, polytetramethylene ether glycol, polyoxypropylene glycol, ethylene oxide diol and / or additive I, and the component B includes hexamethylene diisocyanate, aromatic blocked polyisocyanate, butyl acetate and / or additive II.

[0009] Preferably, the unsaturation degree of the low-unsaturation medium-high molecular weight polyether is 0.15-0.3 and the molecular weight is 10000-15000.

[0010] Preferably, the mass ratio of component A to component B is 10:8.

[0011] Preferably, the component A comprises, by mass, 7-12 parts of low-unsaturation medium-high molecular weight polyether, 7-10 parts of polytetramethylene ether glycol, 5-7 parts of polyoxypropylene glycol, 2-5 parts of ethylene oxide glycol and / or 4-6 parts of additive I.

[0012] Preferably, the B component includes, by mass, 20-30 parts of hexamethylene diisocyanate, 20-23 parts of aromatic blocked polyisocyanate, 10-20 parts of butyl acetate and / or 3-5.5 parts of additive II.

[0013] Preferably, the additive I is one or more of a catalyst, a stabilizer, a pigment, a flame retardant, and a plasticizer. For example, the additive I is a mixture of a catalyst, a stabilizer, a pigment, a flame retardant, and a plasticizer in a mass ratio of 1:1:1:1:1.

[0014] Preferably, the additive II is one or more of a catalyst, a stabilizer, a flame retardant, and a plasticizer, wherein the mass ratio of the catalyst, the stabilizer, the flame retardant, and the plasticizer is 1:1:1:1.

[0015] Here, the catalyst is an amine catalyst, the plasticizer is selected from alkyl sulfonate, cyclohexane oil, diisooctyl phthalate, diisodecyl phthalate, the flame retardant is melamine, and the stabilizer is butylated hydroxytoluene.

[0016] A method for preparing the high temperature resistant polyurethane potting adhesive as described above comprises the following steps:

[0017] S1, mixing low-unsaturation medium-high molecular weight polyether, polytetramethylene ether glycol, polyoxypropylene glycol, ethylene oxide glycol and / or additive I, and performing prepolymerization reaction I at 140-150° C. to obtain component A;

[0018] S2, mixing hexamethylene diisocyanate, aromatic blocked polyisocyanate, butyl acetate and / or additive II, and performing prepolymerization reaction II at 60-70° C. to obtain component B;

[0019] S3, mixing the component A and the component B, pouring them into a mold, and curing them at 30° C. to obtain a high temperature resistant polyurethane potting adhesive.

[0020] Preferably, the reaction time of the prepolymerization reaction I in S1 is 12-24 hours.

[0021] Preferably, the high temperature hardness of the high temperature resistant polyurethane potting glue is 65-72 Shore D.

[0022] The present invention selects low-unsaturation medium-high molecular weight polyether, which has fewer unsaturated bonds (such as double bonds) in its molecular structure, thereby reducing the possibility of oxidative degradation under high temperature conditions. At the same time, the medium-high molecular weight helps to improve the thermal stability and mechanical properties of the polymer. Polytetramethylene ether glycol (PTMEG) and polyoxypropylene glycol have high thermal stability and can maintain good mechanical properties and chemical stability under high temperature conditions. Aromatic polyisocyanate has good heat resistance, and blocked polyisocyanate can be unblocked at high temperature, thereby achieving crosslinking, further improving the thermal stability and mechanical strength of polyurethane. Polyurethane forms a crosslinked network through the reaction of component A and component B, and this crosslinked network can prevent the polymer from softening or flowing at high temperature, thereby maintaining the structural integrity and mechanical strength of the material.

[0023] Compared with the prior art, the beneficial effects of the present invention include:

[0024] The potting glue of the present invention has excellent high temperature and humidity resistance, and can withstand a working temperature of 100-110°C for a long time, so that the material can maintain long-term stability and excellent mechanical properties in the high temperature environment of the fuel cell humidifier. The physical property retention rate can reach more than 90% after being tested at a high temperature of 95°C and a humidity of 95% for 5000 hours. The polyurethane potting glue does not deform or crack when working at a high temperature of 100-110°C for a long time. The present invention also provides a preparation method of the potting glue, which is simple and easy to operate. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0026] Example 1

[0027] Preparation of component A: 10 parts by weight of low-unsaturation medium-high molecular weight polyether with an unsaturation degree of 0.15 and a molecular weight of 10,000, 10 parts by weight of polytetramethylene ether glycol, 5 parts by weight of polyoxypropylene glycol, 5 parts by weight of ethylene oxide glycol, 1 part by weight of catalyst, 1 part by weight of stabilizer, 1 part by weight of pigment, 1 part by weight of flame retardant, and 1 part by weight of plasticizer are added into a reactor in a certain proportion and mixed, and prepolymerization is carried out at a temperature of 140-150° C. to obtain a prepolymer. The stirring reaction time of this process is controlled to be 12-24 hours to ensure the quality of the prepolymer.

[0028] Preparation of component B: 20 ​​parts by mass of hexamethylene diisocyanate, 20 parts by mass of aromatic blocked polyisocyanate, 20 parts by mass of butyl acetate, and 5 parts by mass of additives (the mass ratio of catalyst, stabilizer, flame retardant, and plasticizer is 1:1:1:1) are added into a reactor in a certain proportion and mixed, and prepolymerized at 60°C to obtain component B. The stirring reaction time of this process is controlled within 5h to ensure the quality of the prepolymer. The mixed rubber is subjected to vacuum degassing treatment to remove bubbles and impurities in the rubber. Component A and component B are mixed and stirred evenly in a mass ratio of 10:8, poured into a fixture, and cured at 30°C for 30 minutes to obtain a high-temperature resistant polyurethane potting glue.

[0029] Example 2

[0030] Preparation of component A: 7 parts by mass of low-unsaturation medium-high molecular weight polyether with an unsaturation degree of 0.3 and a molecular weight of 15,000, 7 parts by mass of polytetramethylene ether glycol, 7 parts by mass of polyoxypropylene glycol, 2 parts by mass of ethylene oxide glycol, and 4 parts by mass of additives (a mixture of catalyst, stabilizer, pigment, flame retardant, and plasticizer in a mass ratio of 1:1:1:1:1) are added to a reactor in a certain proportion and mixed, and a prepolymerization reaction is carried out at a temperature of 140-150°C to obtain a prepolymer. The stirring reaction time of this process is controlled to be 12-24 hours to ensure the quality of the prepolymer.

[0031] Preparation of component B: 25 parts by mass of hexamethylene diisocyanate, 23 parts by mass of aromatic blocked polyisocyanate, 15 parts by mass of butyl acetate, and 3 parts by mass of additives (the mass ratio of catalyst, stabilizer, flame retardant, and plasticizer is 1:1:1:1) are added into a reactor in a certain proportion and mixed, and prepolymerized at 60°C to obtain component B. The stirring reaction time of this process is controlled within 5h to ensure the quality of the prepolymer. The mixed rubber is subjected to vacuum degassing treatment to remove bubbles and impurities in the rubber. Component A and component B are mixed and stirred evenly in a mass ratio of 10:8, poured into a fixture, and cured at 30°C for 30 minutes to obtain a high-temperature resistant polyurethane potting glue.

[0032] Example 3

[0033] Preparation of component A: 12 parts by mass of low-unsaturation medium-high molecular weight polyether with an unsaturation degree of 0.2 and a molecular weight of 12,000, 7 parts by mass of polytetramethylene ether glycol, 6 parts by mass of polyoxypropylene glycol, 3 parts by mass of ethylene oxide glycol, and 6 parts by mass of additives (a mixture of catalyst, stabilizer, pigment, flame retardant, and plasticizer in a mass ratio of 1:1:1:1:1) are put into a reactor in a certain proportion and mixed, and a prepolymerization reaction is carried out at a temperature of 140-150°C to obtain a prepolymer. The stirring reaction time of this process is controlled to be 12-24 hours to ensure the quality of the prepolymer.

[0034] Preparation of component B: 30 parts by mass of hexamethylene diisocyanate, 21 parts by mass of aromatic blocked polyisocyanate, 10 parts by mass of butyl acetate, and 5.5 parts by mass of additives (the mass ratio of catalyst, stabilizer, flame retardant, and plasticizer is 1:1:1:1) are added into a reactor in a certain proportion and mixed, and prepolymerized at 60°C to obtain component B. The stirring reaction time of this process is controlled within 5h to ensure the quality of the prepolymer. The mixed rubber is subjected to vacuum degassing treatment to remove bubbles and impurities in the rubber. Component A and component B are mixed and stirred evenly in a mass ratio of 10:8, poured into a fixture, and cured at 30°C for 30 minutes to obtain a high-temperature resistant polyurethane potting glue.

[0035] Comparative Example

[0036] This comparative example is similar to Example 1, except that the saturation degree of the polyether used in this comparative example is 0.8.

[0037] The potting adhesives in Examples 1-3 and the comparative example were tested for performance, and the test results are shown in Table 1.

[0038] Table 1 Performance test data of potting glue

[0039]

[0040] The specific implementation of the present invention described above does not constitute a limitation on the protection scope of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A high temperature resistant polyurethane potting adhesive for a fuel cell humidifier, characterized in that: The raw materials include component A and component B, wherein the component A includes low-unsaturation medium-high molecular weight polyether, polytetramethylene ether glycol, polyoxypropylene glycol, ethylene oxide diol and / or additive I, and the component B includes hexamethylene diisocyanate, aromatic blocked polyisocyanate, butyl acetate and / or additive II.

2. The high temperature resistant polyurethane potting adhesive for fuel cell humidifier according to claim 1, characterized in that: The unsaturation degree of the low-unsaturation medium-high molecular weight polyether is 0.15-0.3 and the molecular weight is 10000-15000.

3. The high temperature resistant polyurethane potting adhesive for fuel cell humidifier according to claim 1, characterized in that: The mass ratio of the component A to the component B is 10:

8.

4. The high temperature resistant polyurethane potting adhesive for a fuel cell humidifier according to claim 3, characterized in that: The component A comprises, by mass, 7-12 parts of low-unsaturation medium-high molecular weight polyether, 7-10 parts of polytetramethylene ether glycol, 5-7 parts of polyoxypropylene glycol, 2-5 parts of ethylene oxide glycol and / or 4-6 parts of additive I.

5. The high temperature resistant polyurethane potting adhesive for fuel cell humidifier according to claim 4, characterized in that: The B component comprises, by mass, 20-30 parts of hexamethylene diisocyanate, 20-23 parts of aromatic blocked polyisocyanate, 10-20 parts of butyl acetate and / or 3-5.5 parts of additive II.

6. The high temperature resistant polyurethane potting adhesive for fuel cell humidifier according to claim 1, characterized in that: The additive I is one or more of a catalyst, a stabilizer, a pigment, a flame retardant, and a plasticizer.

7. The high temperature resistant polyurethane potting adhesive for fuel cell humidifier according to claim 1, characterized in that: The additive II is one or more of a catalyst, a stabilizer, a flame retardant and a plasticizer.

8. A method for preparing the high temperature resistant polyurethane potting adhesive according to claims 1 to 7, characterized in that: The following steps are involved: S1, mixing low-unsaturation medium-high molecular weight polyether, polytetramethylene ether glycol, polyoxypropylene glycol, ethylene oxide glycol and / or additive I, and performing prepolymerization reaction I at 140-150° C. to obtain component A; S2, mixing hexamethylene diisocyanate, aromatic blocked polyisocyanate, butyl acetate and / or additive II, and performing prepolymerization reaction II at 60-70° C. to obtain component B; S3, mixing the component A and the component B, pouring them into a mold, and curing them at 30° C. to obtain a high temperature resistant polyurethane potting adhesive.

9. The preparation method according to claim 8, characterized in that: The reaction time of the prepolymerization reaction I in S1 is 12-24 hours.

10. The preparation method according to claim 8, characterized in that: The high temperature hardness of the high temperature resistant polyurethane potting glue is 65-72 Shore D.

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